This invention relates to a hydrocarbon-soluble composition which is useful in inhibiting the corrosion of a corrodible metal material. More particularly, this invention relates to a hydrocarbon-soluble polyalkylenepolyamine composition comprising a mixture of
(a) at least one C-alkyl-ethylene diamine and PA1 (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)piperazine or mixtures thereof;
wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and pyrazine independently contains from 10 to 28 carbon atoms. This invention also relates to methods for preparing this composition. The invention further relates to a method of inhibiting corrosion in corrodible metals.
Corrosion inhibition in acid systems has been the subject of considerable interest in recent years. In industrial cleaning operations, where aqueous solutions of acid serve to remove scale and other deposits from metallic surfaces of industrial equipment, the inhibitors are used to reduce acid attack on the metals of construction during the cleaning operations. In processing operations where some acid is present or may be generated, inhibitors are introduced to reduce the corrosiveness of the acid. In oil well operations, corrosion inhibitors are introduced during various treatment stages and during secondary recovery operations. In all these operations, the corrosion inhibitor is in a form which is dispersible and preferably miscible in the liquid medium of the particular system.
Since the industrial equipment being protected by the inhibitor is often of considerable value or is often difficult and expensive to replace, significant importance has been given to the development of new and improved corrosion inhibitors. One area of such interest has been the organic inhibitors such as the amines, ketones, sulfides, acetylenic alcohols and the like. In respect to the amines or to their acid salts commonly formed in the acidic systems, fatty amines having one or more amine groups have been recognized as effective inhibitors. Rosin amines have also been used as corrosion inhibitors as have their oxyalkylated derivatives. In addition, various polymeric resins with amine functionalities have been used to some extent. Most of the commercial filming amine corrosion inhibitors are reaction products of fatty acids with ethylene diamine, diethylenetriamine and higher polyamines, resulting in amidoamines and imidazolines.
U.S. Pat. No. 3,770,377 discloses a method for preventing corrosion of metals in an acidic environment by utilizing a corrosion inhibitor which is the reaction product formed by reacting, in the liquid phase and under neutral conditions, at least one carbonyl compound and at least one amine containing a plurality of primary or secondary amino groups. Specific amines taught by this patent include hexamethylene diamine and 1,8-diaminonaphthalene. Specific carbonyl compounds employed include formaldehyde and cyclohexanone.
U.S. Pat. No. 4,554,090 discloses a combination corrosion and scale inhibitor composition comprising the reaction product of (a) a heterocyclic nitrogen-containing compound selected from alkylpyridine, alkylpyrimidine, alkylimidazole, alkylimidazoline, quinoline and quinaldine, (b) an aldehyde, and (c) a phosphoric acid constituent.
U.S. Pat. No. 3,977,981 discloses a method for inhibiting corrosion of corrodible metals utilizing a 14-membered or 16-membered macrocyclic tetramine.
U.S. Pat. No. 4,511,480 discloses a method of inhibiting corrosion of ferrous metals by employing a phosphate ester of an oxyalkylated thiol.
U.S. Pat. No. 4,089,789 discloses a method for inhibiting corrosion of ferrous metal in an acid system utilizing an oxyalkylated phenolic inhibitor comprising the reaction product of (a) an alkylene oxide and (b) a phenolic compound having two non-oxyalkylatable, saturated tertiaryamino alkylene groups.
U.S. Pat. No. 4,388,214 discloses corrosion inhibitors comprising the reaction product of certain imidazolines or precursors thereof and elemental sulfur.
U.S. Pat. No. 4,084,971 discloses a metal protecting composition comprising zinc, a partially hydrolyzed organic silicate, and a fatty acid amidoamine formed by the interaction of an ethylenically unsaturated fatty acid and an alkylene polyamine containing two primary amine groups and at least one secondary amine group wherein the alkylene group contains about 2 to 5 carbon atoms.
U.S. Pat. No. 3,766,053 discloses a method for preventing corrosion utilizing an imidazoline compound formed from the reaction of a naphthenic acid and dipropylene triamine.
U.S. Pat. No. 3,728,277 discloses a corrosion inhibiting composition comprising a mixture of (a) an imidazoline or oxazoline salt of a long chain fatty acid and (b) a salt of a long chain aliphatic amido amine and a long chain aliphatic carboxylic acid.
U.S. Pat. No. 2,940,927 discloses a method of inhibiting corrosion of ferrous metals utilizing the final reaction product obtained by first condensing two moles of a polyamine selected from tetraethylene pentamine, triethylene tetramine, diethylene triamine and ethylene diamine with one mole of a dicarboxylic acid to provide an intermediate bis-imidazoline reaction product, which is then contacted with 1 to 4 moles of ethylene oxide.
U.S. Pat. No. 4,344,861 discloses a method of inhibiting corrosion of metals utilizing the bis-amide reaction product of about one equivalent of a dicarboxylic acid and about one mole ratio of an amine. Among the amines contemplated for use in this method include N-alkyl and N-alkenyl alkylene diamines, wherein the alkylene group contains from 2 to about 10 carbon atoms. Also contemplated are terminally N-substituted polyethylene polyamines, such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylene hexamine.
The preparation of ethylene diamine and other ethylene polyamines is well known in the art. For example, U.S. Pat. No. 1,832,534 discloses the preparation of ethylene diamine by reacting ethylene dichloride with aqueous ammonia at a temperature of about 110.degree. C. and a pressure of about 10 atmospheres.
Similarly, U.S. Pat. No. 2,049,467 describes a procedure for making ethylene polyamines wherein ethylene dichloride and a dilute aqueous solution of ammonia are heated under pressure at temperatures of from 120.degree. C. to 300.degree. C.
U.S. Pat. No. 2,769,841 discloses an improvement in the preparation of ethylene polyamines and polyethylene polyamines by adding diethylenetriamine to a starting mixture of ethylene dichloride and an aqueous solution of ammonia, to reduce the formation of diethylenetriamine and increase the formation of higher polyethylene polyamines.
U.S. Pat. No. 3,751,474 discloses the preparation of relatively high molecular weight polyethylene polyamines by the reaction of ethylene dichloride and aqueous ammonia, using a mole ratio of ammonia to ethylene dichloride of more than 2.6 to 1.
U.S. Pat. No. 4,123,462 describes a process for aminating aliphatic alkane derivatives containing from one to six carbon atoms with ammonia in the presence of a solid nickel-rhenium catalyst, wherein said alkane derivatives are selected from the lower alkanemono-ols, lower alkane diols, lower alkanolamines, and mixtures thereof.
European Patent Application No. 82109001.6 describes a continous process for the manufacture of ethylenediamine from the ethanolamine mixture produced by reacting ethylene oxide with ammonia by providing a continuous monoethanolamine recycle stream to a reaction zone comprising a solid amination catalyst.
East German Pat. No. 149,509 describes a process for the manufacture of a mixture of polyethyleneamines from ethylene oxide and ammonia at high pressure by stepwise non-catalytic reaction with ammonia to produce ethanolamine followed by catalytic reaction with ammonia to produce the polyethyleneamines.
U.S. Pat. No. 4,112,050 discloses a process for removing CO.sub.2 from gaseous feeds using sterically hindered amines. Among the many compounds disclosed is 2,2,5,5-tetramethyldiethylenetriamine (Col. 15, lines 27-31).
U.S. Pat. No. 4,293,682 discloses triamines of the general formula: ##STR1## where R.sup.1 and R.sup.2 can be lower alkyl and R.sup.3 can be hydrogen. The polyamines are useful as epoxy curing agents for polyepoxides.
U.S. Pat. No. 4,629,752 discloses particular highly branched chain polyalkylenepolyamines as starting materials for polysubstituted piperazinones, useful as U.V. stabilizers for polymers. See, for example, structure (IX) in Column 12, lines 41-47. These structures require that the carbon adjacent to the primary amines be disubstituted.
Kempter and Moser in J. Prakt. Chem. 34(1-4), 104-11 (1966), CA 66:28324v describe the preparation of even-numbered 1,2-diamines from chromatographically pure even-numbered fatty acids. This procedure involves preparing the 2-bromo-acid, reacting it with thionyl chloride and then ammonia to produce the 2-bromo-amide, reacting the amide with 40-80 equivalents of aqueous ammonia to produce the 2-amino-amide and then reducing this product with lithium aluminum hydride. Aliphatic 1,2-diamines up to C.sub.18 are disclosed.
U.S. Pat. No. 2,736,658 discloses aliphatic diamines of the structure: ##STR2## wherein R represents an aliphatic or alicyclic carbon chain attached to nitrogen of from 8-22 carbon atoms and x is a number from 2-10. Preferably, x is 3. These compounds are described as corrosion inhibitors, the effectiveness increasing greatly when the diamines are employed in the form of their fatty or rosin acid salts.
Prior art corrosion inhibitors are generally N-alkyl-amines or polyamines, wherein the alkyl group is typically in the detergent range. We have now surprisingly discovered that when this alkyl group is attached to carbon rather than nitrogen, polyalkylenepolyamine compositions having improved corrosion inhibiting characteristics are obtained.